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A Five-Kingdom Survey Kingdom Monera

A Five-Kingdom Survey Kingdom Monera

• In , organisms are classified into categories called taxa (singular, taxon).

• A Species is given a name consisting of a species name and a Genus (plural, genera) name. A Five- Survey For example, the domesticated dog is categorized into the genus Canis and is given the name Canis familiaris.

Closely related are grouped in the same genus. Thus, the wolf, Canis lupis, and the coyote, Canis latrans, share the same genus with the domesticated dog.

The Five Kingdom The Five Kingdom 2 Dr. Abboud ElKichaoui 1 Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department

Mephitis Lutra Canis Felis Canis mephitis lutra familiaris SPECIES catus lupus Genera that share related features are grouped in a Family. (striped (European (domestic (domestic (wolf) cat) skunk) otter) dog) Related families, in turn, are grouped in Orders, which are grouped successively in Classes, Phyla (singular, phylum) (or divisions for fungi and ), and finally, kingdoms.

A good way to remember the successional order of taxa is to remember the phrase “ GENUS Felis Mephitis Lutra Canis Kings Play Chess On Fine Green Sand,” in which each word gives the first letter of each taxon from kingdom to species. FAMILY Felidae Mustelidae Canidae

ORDER Carnivora

The Five Kingdom The Five Kingdom 4 Dr. Abboud ElKichaoui 3 Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department

Kingdom Monera Five kingdoms are currently used to categorize all organisms. •The single, distinguishing characteristic The characteristics of each of these kingdoms, and important taxa of organisms in the kingdom Monera is within these kingdoms, are described below. that they are . As prokaryotes, they lack nuclei and the various organelles of .

•Prokaryotes possess a single “naked” chromosome consisting of a single DNA molecule without the proteins found in eukaryotes. MONERA PROTISTA PLANTAE FUNGI ANIMALIA •Some prokaryotes have plasmids, small circular DNA molecules, in addition to the major chromosome. • •The walls of most prokaryotes contain , a polysaccharide modified with polypeptides. In contrast, the cell walls of plants contain cellulose. The Five Kingdom The Five Kingdom 6 Dr. Abboud ElKichaoui 5 Dr. Abboud ElKichaoui Islamic University- Biology Department Islamic University- Biology Department

1 Currently, many prokaryotes are organized by their mode of Flagella, when present in monerans, consist of the globular protein flagellin nutrition, that is, how they metabolize resources, as follows: arranged in helical chains (not tubulin arranged in 9 + 2 microtubule arrays as in eukaryotes). ﺣرﻛﺔ اﻟﻣﻔﺗﺎح 1. Autotrophs Prokaryotes without flagella move by a corkscrew motion, while still others may exhibit a gliding motion through slimy material that they secrete. ﺣرﻛﺔ اﻧزﻻﻗﯾﺔ .Autotrophs manufacture their own organic compounds To do this, We have: Photoautotrophs use light energy (as in ) and Chemoautotrophs use energy obtained from inorganic substances (as in chemosynthesis). Examples of inorganic substances used by chemoautotrophs are:

-hydrogen sulfide (H2S), -ammonia (NH3), and -other nitrogen compounds (NO2–, NO3–). The Five Kingdom 8 Dr. Abboud ElKichaoui 7 Islamic University- Biology Department

2. Heterotrophs Another feature important in describing prokaryotes is their Heterotrophs must obtain their energy by consuming organic ability to survive in the presence or absence of oxygen. substances produced by autotrophs.

– Obligate aerobes must have oxygen to live. Some heterotrophic are Parasites, obtaining their energy from the living tissues of a host. – Obligate anaerobes can survive only in the absence of oxygen. Others are Saprobes (or saprophytes), obtaining their energy from dead, decaying matter. Since saprobes contribute to the decay of organic matter, – A facultative anaerobe grows in the presence of oxygen but, when they are called Decomposers. oxygen is absent, can switch to an anaerobic metabolism. Others are Symbiotic obtaining their energy from a symbiotic relationships with their host (Plants, animals act…)

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Archaebacteria Molecular analysis has revealed two distinct groups within the Monera,

Archaebacteria are distinguished by these three • The Eubacteria (“true” bacteria) and major features: • The Archaebacteria.

1. Their cell walls lack peptidoglycans. 2. Their ribosomes are more similar to ribosomes of eukaryotes than to those of eubacteria. 3. Their plasma membranes contain lipids that differ from those found EUBACTERIA in the plasma membranes of all other organisms.

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2 Eubacteria Various features are used to categorize the Eubacteria, as follows:

1. The principal means by which the eubacteria are categorized is by their mode of nutrition, or how they metabolize resources. 3. Eubacteria are distinguished by their means of motility, whether by flagella, 2. Some eubacteria are distinguished by their ability to produce , gliding, or corkscrew motion. When resistant bodies that contain the genetic material and a small amount of cytoplasm surrounded by a durable wall. flagella are present, they can be apical or posterior, or they can completely cover the cell.

Endospore

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5. The distinguishes two broad groups of bacteria. Bacteria that stain positive with the Gram stain have a thick 4. Bacteria are classified into one of three shapes: cocci (spherical), bacilli technique (rod shaped), and spirilla (spirals). cell wall, while Gram-negative bacteria have a thin peptidoglycan wall Gram-positive covered with a layer of lipopolysaccharides.

Gram-negative

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Some of the more common groups of bacteria follow: Some have specialized cells called heterocysts that produce nitrogen-fixing enzymes. 1. Cyanobacteria are photosynthetic, using chlorophyll a to capture light energy, splitting H2O, and releasing O2 as do plants. They also contain accessory pigments called phycobilins.

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3 4. Spirochetes are coiled bacteria that move with a corkscrew motion. Their flagella are internal, positioned within the layers of the cell wall. 2. Chemosynthetic bacteria are autotrophs.

Some of these are called nitrifying bacteria because they convert nitrite (NO2–) to nitrate (NO3–).

3. Nitrogen-fixing bacteria are heterotrophs that fix nitrogen.

Many of these bacteria have mutualistic relationships with plants; that is, both the bacteria and the host benefit from an interdependent relationship. The bacteria live in nodules, specialized structures in plant roots. nodules

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Kingdom Protista A) Algaelike Organisms in this kingdom may be: algaelike, animallike, funguslike, unicellular, or multicellular.

Algaelike (or plant-like) members of the Protista all obtain energy by photosynthesis.

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2. Dinoflagellata, or dinoflagellates, have two flagella. One flagellum is posterior, while the second flagellum is transverse and rests in an encircling mid groove perpendicular to the first flagellum.

Some distinguishing characteristics of the phyla follow:

1. Euglenophyta, or euglenoids, have one to three flagella at their apical (leading) end.

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4 5. Chlorophyta, or green , have both chlorophyll a and b, have cellulose cell 3. Chrysophyta, or golden algae, are golden yellow and have one or two apical walls, and store their carbohydrates as starch. There is considerable variation in flagella. sexuality.

Plastid

4. Bacillariophyta, or diatoms, have tests (shells) that consist of silica (SiO2).

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6. Phaeophyta, or brown algae, are multicellular and have flagellated sperm cells. Some brown algae are giant seaweeds, or kelps.

Because of these various characteristics and evolutionary trends, the Chlorophyta are believed to be the ancestors of plants.

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7. Rhodophyta, or red algae, B) The contain red accessory pigments called phycobilins. They are multicellular, and their gametes do not have flagella. The protozoa, or -like , are heterotrophs. They consume either living cells (thus being predatory or parasitic) or dead organic matter.

Some important phyla follow:

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5 2. Foraminifera, or forams, have tests (shells )usually made of 1. Rhizopoda are amoebas that move by extensions of their cell body called calcium carbonate. pseudopodia. Pseudopodia encircle food and absorb it by phagocytosis.

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4. Sporozoa are parasites of animals. They have no physical means of motility. 3. Zoomastigophora, or zooflagellates, are flagellated protozoa. However, they form spores which are dispersed by one or more hosts that Some mutualistic species digest cellulose in the guts of termites. participate in the completion of their cycles. Others are parasites, such as Trypanosoma, which is The sporozoan that causes malaria, for example, spends part of its life cycle transmitted by the tsetse fly and causes African sleeping sickness in humans. in mosquitos and part in humans.

The life cycles of Plasmodium

Trypanosoma Trichonympha : symbiont in termite gut The Five Kingdom 34 33 Dr. Abboud ElKichaoui Islamic University- Biology Department

C) The -like protists 5. Ciliophora are distinguished by their cilia, which they use for moving and other functions. The fungus-like protists resemble fungi because they form either filaments or spore-bearing bodies similar to the fungi. Because of specialized structures, such as mouths, anal pores, contractile vacuoles (for water balance), two kinds of nuclei (one large macronucleus and several small micronuclei), and other features, they are perhaps the most 1. Acrasiomycota, the cellular slime molds, exhibit both complex of all cells. funguslike and protozoalike characteristics during their life cycle. Paramecium is this phylum’s most notable member.

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6 3. Oomycota include ,Myxomycota .2 ,ﻋﻔن اﻟﻣﯾﺎه the water molds ,ﺑﯾﺎض زﻏﺑﻲ downy mildews Called also plasmodial slime molds, grow as a single, spreading .اﻟﺻدأ اﻷﺑﯾض and white rusts They are either parasites or saprobes. mass (or plasmodium) feeding on decaying vegetation.

A water mold

37 Downy mildew grapes infection White rust on cabbage

Some fungi have septa (singular, septum), or cross walls, which divide the Kingdom Fungi filament into compartments containing a single nucleus. When filaments lack septa, they are multinucleate, or coenocytic. Fungi grow as filaments called hyphae (singular, hypha). A mass of hyphae is The cell walls of fungi consist of chitin, a nitrogen containing polysaccharide. called mycelium (plural, mycelia).

Hypha

Septate hyphae nonseptate hyphae 40 39 Mycelium

Many parasitic fungi have hyphae called haustoria that penetrate their host.

•Fungi are either parasites or saprobes, absorbing the breakdown products from the action of digestive enzymes that they secrete.

7 Fungi reproduce sexually and asexually Asexuall reproduction occurs by various means, including • fragmentation (the breaking up of hyphae), • budding (the pinching off of a small hyphal outgrowth), • and asexual spores. Two kinds of asexual spores are described below: sexual reproduction 1. Sporangiospores are produced in saclike capsules called sporangia (singular, sporangium) that are each borne on a stalk called a Fungi are dominantly haploid, but most form sporangiophore. temporary diploid structures for sexual 2. Conidia (singular, conidium) are formed at the tips of specialized hyphae, reproduction. not enclosed inside sacs. Hyphae bearing conidia are called conidiophores.

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• 2. Karyogamy is the fusing of the two haploid nuclei of a dikaryon to The following stages occur during sexual reproduction. form a single diploid nucleus. • 1. Plasmogamy is the fusing of cells from two different fungal strains to produce a single cell with nuclei from both strains. A pair of haploid • 3. Meiosis of the diploid nucleus restores the haploid condition. nuclei, one from each strain, is called a dikaryon. A hypha containing a Daughter cells develop into haploid spores, which germinate and dikaryon is called a dikaryotic hypha. form haploid hyphae.

2 Diploid nuclei 3 Spores 2 Diploid nuclei 3 Spores released released 1 Fruiting body 1 Fruiting body (mushroom) (mushroom)

Haploid Haploid nucleus nucleus DIPLOID DIPLOID Spore Spore

HAPLOID HAPLOID DIKARYOTIC DIKARYOTIC

4 Germination of spores 4 Germination of spores and growth of mycelia and growth of mycelia 6 Growth of 6 Growth of dikaryotic mycelium 5 Fusion of two hyphae dikaryotic mycelium 5 Fusion of two hyphae of compatible mating types of compatible mating types

lack septa, except when •The fungi form three natural groups based on sexual (اﻟﻔطرﯾﺎت اﻟزﯾﺟوﺗﯾﺔ أو اﻻﻗﺗراﻧﯾﺔ) Zygomycota .1 filaments border reproductive filaments. Zygomycetes reproduce sexually by fusion of hyphae from different strains, followed by reproduction. The fourth group, the imperfect fungi are plasmogamy, karyogamy, and meiosis. Haploid zygospores are not a true division, but rather a collection of fungi in produced, which germinate into new hyphae. Bread mold is a typical zygomycete. which sexual structures have not been identified.

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8 have septa and reproduce sexually by (اﻟﻔطرﯾﺎت اﻟﻛﯾﺳﯾﺔ أو اﻟزﻗﯾﺔ) Ascomycota .2 producing haploid ascospores. After plasmogamy of hyphae from unlike strains, a dikaryotic hypha produces more filaments by . Karyogamy and ( اﻟﻛﻣﺄة) Truffles meiosis subsequently occur in terminal hyphal cells producing four haploid cells. These four cells divide by mitosis to produce eight haploid ascospores in a sac called an ascus (plural, asci). In many ascomycetes, the asci are grouped together into a specialized fruiting body, the ascocarp. The .(اﻟﻛﻣﺄة) and truffles ,(اﻟﺑﯾﺎض اﻟدﻗﯾﻘﻲ) ascomycetes include yeasts, powdery mildews

have septa and reproduce (ﻗﺳم اﻟﻔطرﯾﺎت اﻟﺑﺎزﯾدﯾﺔ أو اﻟدﻋﺎﻣﯾﺔ) Basidiomycota .3 .or imperfect fungi, is an sexually by producing haploid basidiospores ,( ﻗﺳم اﻟﻔطرﯾﺎت اﻟﻧﺎﻗﺻﺔ) Deuteromycota .4 artificial group comprising fungi for which no sexual reproductive Plasmogamy between two unlike hyphae is followed by mitosis and the cycle has been observed. Penicillium, from which penicillin is growth of dikaryotic hyphae to form a fruiting body called a basidiocarp. A mushroom, for example, is a basidiocarp. Karyogamy occurs in obtained, is a deuteromycete. terminal hyphal cells called basidia (singular, basidium), followed by meiosis and the production of four haploid basidiospores.

6. Mycorrhizae are mutualistic associations between 5. Lichens are mutualistic associations between fungi and algae. fungi and roots of plants. The plant provides sugars to The algae, which is usually a chlorophyta or cyanobacteria, the fungus, while the fungus increases the ability of the provides sugar from photosynthesis. Nitrogen compounds are roots to absorb water and minerals, especially also provided if the algae is nitrogen-fixing. The fungus, which is most often an ascomycete, provides water and protection from phosphorus. the environment. Some fungi produce pigments that shield algae from ultraviolet radiation or excess light, or toxic substances that discourage algae consumption by grazers.

Algal cell

Fungal hyphae

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